Whiteboard is often used in work and life to make record or discuss. For example, in teaching and meeting, the character, symbol and so on can be written on the whiteboard and can be erased conveniently. However, the content written on traditional whiteboard is appeared only one time; it can't be stored and reproduced. Therefore, traditional whiteboard dose not satisfy the requirement of current digitized life and work.
Electronic whiteboard is used in teaching environment in school and is used in studying and discussing procedure in a department, along the development of electronic technology. Such product can promptly convert the symbols written on the whiteboard into electronic signal, then transfers the electronic signal to a computer connected thereto. Editing, printing, transmission and remote information switching etc. can be completed immediately by the computer. For existing electronic whiteboard with large induction area, it is impossible to manufacture the electromagnetic induction typed electronic whiteboard by, for example, etching the printed circuit board, and it is also impossible to manufacture the resistance-induction typed electronic whiteboard by using the touching screen because of high cost. Therefore, the ultrasonic wave transmission and reception between input pen and electronic whiteboard is used in order to control and operate. But such product is not applied widely due to the high cost and low accuracy. Therefore, this phase of information generation and intercourse can't be digitized widely and fast.
In conclusion, existing product has many disadvantages, such as: very low identification ratio, poor accuracy, high cost, and difficulty in manufacture, which limit wide application of such product.